Continuous casting has been known in which a molten metal melted in a melting furnace is supplied to a moving mold constituted by rolls, belts, etc., from a tundish, and cooled and solidified by being brought into contact with the moving mold so as to continuously produce cast materials. Molten metal is supplied to the moving mold via a nozzle. Examples of this nozzle for casting include those described in Patent Literatures 1 and 2. In Patent Literature 1, a nozzle having a tip having a three-layer structure that includes a high-heat-conductivity layer, a low-heat-conductivity-layer, and a high-strength elastic layer is disclosed which reduces variation in the temperature of the molten metal in the width direction of the material during casting. Patent Literature 2 discloses a nozzle suitable for use in continuous casting of pure magnesium or magnesium alloys. This nozzle includes a main body composed of an oxide material in order to prevent reaction between the nozzle-forming material and the molten metal of magnesium which is an active metal, and a coating layer composed of a low-oxygen material and disposed on a surface of the main body that contacts the molten metal.